docs: def ip_quad_to_numstr(quad):
      """
      Convert an IP address string (e.g. '192.168.0.1') to an IP
      number as a base-10 integer given in ASCII representation.
  
      >>> ip_quad_to_numstr('192.168.0.1')
      '3232235521'
      """
      bytes = map(int, quad.split("."))
      packed = struct.pack('BBBB', *bytes)
      return str(struct.unpack('>L', packed)[0])